• Roy, S. Le
• Boudou, L.
• Teyssedre, Gilbert
• Hoang, M-Q

Abstract

The aim of this work is to highlight the polarization mechanisms in the time-and frequencydomains, and to implement the contribution of the polarization to the dielectric response into a charge transport model. To do so, Alternate Polarization Current (APC) and Dielectric Spectroscopy (DS) measurements have been performed on poly(ethylene naphthalene 2,6-dicarboxylate) (PEN), an aromatic polar material, providing information on polarization mechanisms in the time-domain and frequency-domain respectively. In the frequency-domain PEN exhibits 3 relaxation processes termed β, β * (sub-glass transitions) and α relaxations (glass transition) in increasing order of temperature. Conduction was also detected at high temperatures. Dielectric responses were treated using a simplified version of the Havriliak-Negami (HN) model (Cole-Cole (CC) model), using 3 parameters per relaxation process, function of the temperature. The time dependent permittivity obtained from the CC model is then added to a charge transport model. Simulated currents issued from the transport model implemented with the polarization are compared to the measured APC currents, showing a good consistency between experiments and simulations in a situation where the response is essentially from dipolar processes.

Topics

• impedance spectroscopy
• experiment
• simulation
• glass
• glass